PDA

View Full Version : Will Sigma 70-200 f/2.8 work with Canon 1.4x TC

AzzKicker
23rd of July 2004 (Fri), 10:44
I'm about to make a deal for a Canon 1.4x TC.


Is my Sigma 70-200 f/2.8 compatible with the CANON TC?
Jon
23rd of July 2004 (Fri), 10:55
Take a look at the rear lens element on the 70-200. The Canon 1.4x TC has a front element that protrudes several mm. forward of the lens mount. From memory, between 4-5 mm. Figure you'd need at least 1 cm. clearance (run through the zooming and focussing ranges to make sure), and make sure that the lens tube in back of the rear element is pretty wide since it'll have to accomodate a (again from memory) 2-3 cm diameter lens element. If you have any of the Canon lenses that are listed as compatible with the TC, use one of them as a role model in deciding whether it might clear.
AzzKicker
23rd of July 2004 (Fri), 11:42
I just confirmed it on another site. It wont fit :(
Cadwell
23rd of July 2004 (Fri), 14:07
I just confirmed it on another site. It wont fit :(

Really? That does surprise me. Sigma state that the lens is compatible with their teleconvertors and they are a very simillar design physically to the Canon ones.
CyberDyneSystems
23rd of July 2004 (Fri), 15:38
I'm sorry to say I never tried it that way around.. but I too am surprised.

I used to own the lens in question.. and I still own the Sigma 1.4X t-con whch WILL work with ANY Canon lens that will work with the Canon T-cons... and the Canon T-cons do work with every Sigma lens I have tried them with.. (as I said I have not tried this combo though,.. and of course I only mean the Sigma Lenses that Sigma specs for use with there own T-cons)

It was my understanding the Sigma and Canon T-cons were pretty much universally interchangeable. (image quality difereces aside)
Jon
23rd of July 2004 (Fri), 15:42
The Canon TCs elements protrude forward of the front of the housing. Not much in the 1.4x, maybe more on the 2.0x. The FD 1.4x had a fairly large protrusion, so it's nothing new with Canon. Do Sigmas have these protruding front elements?
Cadwell
23rd of July 2004 (Fri), 15:54
The Canon TCs elements protrude forward of the front of the housing. Not much in the 1.4x, maybe more on the 2.0x. The FD 1.4x had a fairly large protrusion, so it's nothing new with Canon. Do Sigmas have these protruding front elements?

Yes, they do.